From a8a26a52998e71d5bf287f91700d21a52fadee45 Mon Sep 17 00:00:00 2001
From: Gao Sun <gao@silverhand.io>
Date: Sat, 29 Jul 2023 17:44:03 +0800
Subject: [PATCH] refactor(console): report reddit conversion (#4263)

* refactor(console): report reddit conversion

* refactor(console): update pixel id
---
 packages/console/jest.setup.ts                | 11 +++++
 .../src/components/ReportConversion/index.tsx | 28 ++++++++++++
 .../components/ReportConversion/utils.test.ts | 24 ++++++++++
 .../src/components/ReportConversion/utils.ts  | 45 +++++++++++++++++--
 packages/console/src/include.d/tags.d.ts      |  4 ++
 5 files changed, 108 insertions(+), 4 deletions(-)
 create mode 100644 packages/console/src/components/ReportConversion/utils.test.ts

diff --git a/packages/console/jest.setup.ts b/packages/console/jest.setup.ts
index a14c86087..233334651 100644
--- a/packages/console/jest.setup.ts
+++ b/packages/console/jest.setup.ts
@@ -1,3 +1,6 @@
+import { webcrypto } from 'node:crypto';
+import { TextEncoder, TextDecoder } from 'node:util';
+
 import i18next from 'i18next';
 import { initReactI18next } from 'react-i18next';
 
@@ -7,3 +10,11 @@ void i18next.use(initReactI18next).init({
   lng: 'en',
   react: { useSuspense: false },
 });
+
+/* eslint-disable @silverhand/fp/no-mutation */
+// @ts-expect-error monkey-patch for `crypto`
+crypto.subtle = webcrypto.subtle;
+global.TextEncoder = TextEncoder;
+// @ts-expect-error monkey-patch for `TextEncoder`/`TextDecoder`
+global.TextDecoder = TextDecoder;
+/* eslint-enable @silverhand/fp/no-mutation */
diff --git a/packages/console/src/components/ReportConversion/index.tsx b/packages/console/src/components/ReportConversion/index.tsx
index 2ed523127..6fc8a209d 100644
--- a/packages/console/src/components/ReportConversion/index.tsx
+++ b/packages/console/src/components/ReportConversion/index.tsx
@@ -1,6 +1,8 @@
 import { useEffect } from 'react';
 import { Helmet } from 'react-helmet';
 
+import useCurrentUser from '@/hooks/use-current-user';
+
 import {
   shouldReport,
   lintrk,
@@ -8,6 +10,9 @@ import {
   linkedInConversionId,
   gtag,
   gtagSignUpConversionId,
+  rdt,
+  redditPixelId,
+  hashEmail,
 } from './utils';
 
 /**
@@ -15,6 +20,28 @@ import {
  * Insight Tag, then reports a sign-up conversion to them.
  */
 export default function ReportConversion() {
+  const { user, isLoading } = useCurrentUser();
+
+  /**
+   * Initiate Reddit Pixel and report a sign-up conversion to it when user is loaded.
+   * Use user email to prevent duplicate conversion, and it is hashed before sending
+   * to protect user privacy.
+   */
+  useEffect(() => {
+    const report = async () => {
+      rdt('init', redditPixelId, {
+        optOut: false,
+        useDecimalCurrencyValues: true,
+        email: await hashEmail(user?.primaryEmail ?? undefined),
+      });
+      rdt('track', 'SignUp');
+    };
+
+    if (shouldReport && !isLoading) {
+      void report();
+    }
+  }, [user, isLoading]);
+
   /**
    * This `useEffect()` initiates Google Tag and report a sign-up conversion to it.
    * It may run multiple times (e.g. a user visit multiple times to finish the onboarding process,
@@ -49,6 +76,7 @@ export default function ReportConversion() {
           src={`https://www.googletagmanager.com/gtag/js?id=${gtagAwTrackingId}`}
         />
         <script async src="https://snap.licdn.com/li.lms-analytics/insight.min.js" />
+        <script async src="https://www.redditstatic.com/ads/pixel.js" />
       </Helmet>
     );
   }
diff --git a/packages/console/src/components/ReportConversion/utils.test.ts b/packages/console/src/components/ReportConversion/utils.test.ts
new file mode 100644
index 000000000..cc086be03
--- /dev/null
+++ b/packages/console/src/components/ReportConversion/utils.test.ts
@@ -0,0 +1,24 @@
+import { hashEmail } from './utils';
+
+describe('hashEmail()', () => {
+  it('should return undefined if the given email is falsy', async () => {
+    expect(await hashEmail()).toBeUndefined();
+    expect(await hashEmail('')).toBeUndefined();
+    expect(await hashEmail(' ')).toBeUndefined();
+  });
+
+  it('should return undefined if the given email is invalid', async () => {
+    expect(await hashEmail('foo')).toBeUndefined();
+    expect(await hashEmail('foo@')).toBeUndefined();
+    expect(await hashEmail('@foo')).toBeUndefined();
+    expect(await hashEmail('foo@bar@baz')).toBeUndefined();
+    expect(await hashEmail('foo@ bar .@')).toBeUndefined();
+  });
+
+  it('should return the hash of the canonicalized email', async () => {
+    const hash = 'ff8d9819fc0e12bf0d24892e45987e249a28dce836a85cad60e28eaaa8c6d976';
+    expect(await hashEmail('alice@example.com')).toBe(hash);
+    expect(await hashEmail('Al.ice+Apple@Example.Com')).toBe(hash);
+    expect(await hashEmail('  a.Lice+@example.com')).toBe(hash);
+  });
+});
diff --git a/packages/console/src/components/ReportConversion/utils.ts b/packages/console/src/components/ReportConversion/utils.ts
index 1c6afb05a..9c453aec8 100644
--- a/packages/console/src/components/ReportConversion/utils.ts
+++ b/packages/console/src/components/ReportConversion/utils.ts
@@ -12,7 +12,7 @@ export const linkedInConversionId = '13374828';
  */
 export const shouldReport = window.location.hostname.endsWith('.' + logtoProductionHostname);
 
-/* eslint-disable @silverhand/fp/no-mutation, @silverhand/fp/no-mutating-methods */
+/* eslint-disable @silverhand/fp/no-mutation, @silverhand/fp/no-mutating-methods, prefer-rest-params */
 
 /** This function is edited from the Google Tag official code snippet. */
 export function gtag(..._: unknown[]) {
@@ -21,7 +21,7 @@ export function gtag(..._: unknown[]) {
   }
 
   // We cannot use rest params here since gtag has some internal logic about `arguments` for data transpiling
-  // eslint-disable-next-line prefer-rest-params
+
   window.dataLayer.push(arguments);
 }
 
@@ -37,8 +37,45 @@ export function lintrk(..._: unknown[]) {
     window.lintrk = { q: [] };
   }
 
-  // eslint-disable-next-line prefer-rest-params
   window.lintrk.q.push(arguments);
 }
 
-/* eslint-enable @silverhand/fp/no-mutation, @silverhand/fp/no-mutating-methods */
+/**
+ * This function will do the following things:
+ *
+ * 1. Canonicalize the given email by Reddit's rule: lowercase, trim,
+ * remove dots, remove everything after the first '+'.
+ * 2. Hash the canonicalized email by SHA256.
+ */
+export const hashEmail = async (email?: string) => {
+  if (!email) {
+    return;
+  }
+
+  const splitEmail = email.toLocaleLowerCase().trim().split('@');
+  const [localPart, domain] = splitEmail;
+
+  if (!localPart || !domain || splitEmail.length > 2) {
+    return;
+  }
+
+  // eslint-disable-next-line unicorn/prefer-string-replace-all
+  const canonicalizedEmail = `${localPart.replace(/\./g, '').replace(/\+.*/, '')}@${domain}`;
+  const hash = await crypto.subtle.digest('SHA-256', new TextEncoder().encode(canonicalizedEmail));
+
+  // https://stackoverflow.com/questions/40031688/javascript-arraybuffer-to-hex
+  return [...new Uint8Array(hash)].map((value) => value.toString(16).padStart(2, '0')).join('');
+};
+
+export const redditPixelId = 't2_ggt11omdo';
+
+/** Report Reddit conversion events. */
+export function rdt(..._: unknown[]) {
+  if (!window.rdt) {
+    window.rdt = { callQueue: [] };
+  }
+
+  window.rdt.callQueue.push(arguments);
+}
+
+/* eslint-enable @silverhand/fp/no-mutation, @silverhand/fp/no-mutating-methods, prefer-rest-params */
diff --git a/packages/console/src/include.d/tags.d.ts b/packages/console/src/include.d/tags.d.ts
index 5dc207007..1fe6b58e7 100644
--- a/packages/console/src/include.d/tags.d.ts
+++ b/packages/console/src/include.d/tags.d.ts
@@ -6,4 +6,8 @@ declare interface Window {
   lintrk?: {
     q: unknown[];
   };
+  // Reddit
+  rdt?: {
+    callQueue: unknown[];
+  };
 }